MP5032

– QC 3.0 CONTROLLER WITH CURRENT-LIMIT SWITCH

MP5032 Rev r1.0

www.MonolithicPower.com

12

8/4/2017

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© 2017 MPS. All Rights Reserved.

OPERATION

The MP5032 integrates a USB current-limit

switch and charging port identification circuit.

The MP5032 achieves 3A of continuous output

current over a wide input supply range.

The output of the USB switch is current-limited

with an adjustable current-limit threshold. The

MP5032

supports

the

latest

quick-charge

specification

(QC

3.0)

and

is

backwards-

compatible with QC 2.0. The MP5032 also

supports DCP schemes for battery charging

specification

(BC1.2),

divider

mode,

and

1.2V/1.2V mode without the need for external

user interaction.

The MP5032 provides line drop compensation

for a 5V output. Fault condition protection

includes hiccup current limiting, input over-

voltage

protection

(OVP),

and

thermal

shutdown.

Operation Supply Voltage

The MP5032 has a two-stage input voltage

threshold. The first threshold is around 3V, and

the second threshold is the under-voltage

lockout (UVLO) of the power MOSFET. When

MP5032's ADJ block starts working and sinks a

current to adjust the upstream regulator's output

to an accurate 5.1V. Afterward, the MP5032

can enable the power MOSFET to fully enter

the working state.

Under-Voltage Lockout (UVLO)

UVLO protects the chip from operating at an

insufficient

supply

voltage.

The

MP5032's

second UVLO comparator monitors the input

voltage. Once the input voltage is higher than

3.9V, the power MOSFET starts to turn on with

a controlled slew rate.

Internal Soft Start (SS)

An internal soft start prevents the output voltage

from inrush current and overshooting during

start-up.

QC Mode Voltage Transition - Class A

If the downstream device of the MP5032

supports the QC specification, the MP5032 can

require a output voltage higher than 5V by DM

and DP communication. If a higher USB bus

voltage is required, ADJ must be used. ADJ is

usually connected to the feedback pin of the

upstream

voltage

converter.

After

the

handshake, the MP5032 sinks a controlled

9V/12V or another voltage 200mV step-by-step.

Because of smart controller mode, only one

ADJ pin can be set to a different high voltage

that meets QC specification. The output voltage

transition is smooth and has no undershoot or

overshoot (see Figure 2 and Table 1).

5V

9V

12V

DP=0.6V

DM=GND

DP=0.6V

DM=0.6V

DP=3.3V

DM=0.6V

Figure 2: QC Mode Transition

Table 1: QC Mode Definition

Portable Device

USB Bus Voltage

DP

DM

0.6V

0.6V

12V

3.3V

0.6V

9V

0.6V

3.3V

3.6V - 12V/200mV step

according to QC 3.0

3.3V

3.3V

No action

0.6V

GND

5V

When the downstream device is removed, the

output

voltage

returns

to

the

default

5V

automatically. The input-to-ground discharge

resistor helps expedite this procedure.

Line Drop Compensation

The MP5032 is capable of compensating for an

output voltage drop, such as high impedance

caused by a long trace, to maintain a fairly

constant 5V load-side voltage. The line drop

disabled under QC 3.0 mode. Line drop

compensation is achieved through ADJ. The

MP5032 increases the input voltage by 330mV

at a 2.4A output current. Refer to the Line Drop

Compensation

graph

in

the

Typical

Performance Characteristics section on page 6.

current. The line drop compensation amplitude

increases linearly as the load current increases.